Furnace.



No. 799,316. PATENTED MAY 9, 1905. R. G. BLOOMPIELD.

PURNAGE.

APPLICATION FILED MAY 16,1904.

2 SHEETS-SHEET 1.

No. 789,316. PATENTED MAY 9, 1905. R. G. BLOOMFIELD.

FURNAGB.

APPLICATION FILED MAY 16,1904.

2 SHEETS-SHEET 2.

Patented May 9, 1905.

FUHNCE..

SPECIFICATION forming part of Letters Patent No. 789,316, dated May 9,1905.

` Application fllel May 16, 1904. Serial No. 208,249.

To /tZZ 11171/0771/ 'it 71mg/ con/cern:

Be it known that I, ltUss ELL C. BLooMrInLD, a citizen of the UnitedStates, residing at Boele ford, in the county of Winnebago and State ofIllinois, have invented a new and useful Furnace, of which the followingis a specilication.

',lhis invention relates to furnaces, and more particularly to furnacesof the type employed in carbonizing and decarbonizing iron and steel.

The invention has for its principal object the provision of a furnace ofthe type specified in which the maximum heating effect may be obtainedfrom the fuel used, uniformity be secured in the distribution oftheheat, and a general improvement produced in the character of the resultsof the operation of the furnace.

As is well known, the carbonizing and deearbonizing of iron and steel isusually effected by placing' the metal to be treated in a box ofsuitable size together with a compound of suitable character to effectcarbonization or decarbonization, then subjecting the box so filled tothe action of heat in a furnace for a sufficient length of time to bringabout the desired chemical action. '.lhe boxes employed in this processvary in leng'th according to the length of the pieces of metal to betreated, and in some instances it is necessary to employ boxes of tenfeet or more in length. The furnaces ordinarily employed in carrying outthe process outlined are circular in form, with the grates arranged atone side thereof and a chimney or smokestack at the opposite side, thehearth or iioor of the furnace being' retatably supported and providedwith means for impe 'ting rotation thereto in order to bring each boxsuccessively into the portion of the furnace in which the maximum heatis pro duced. By means of a furnace of this character it is possible toproduce tolerably satisfactory results in carbouizing or decarbonizingiron and steel; but the fuel employed is not economically used, and thefurnaces and boxes are subjected to unnecessarily high temperatures,with deleterious results to both.

In the invention forming the subject of the present application thedesign of the furnace has been changed in a radical manner to effect theuniform distribution of heat within the flame-chamber of the furnace inorder that the boxes may not be subjected at any step of the process toextremely high temperatures and in order to avoid the injurious effectsupon the furnace of extreme heat in one part with less heat in another.The furnace has also been designed with a view to the elimination ofunnecessary space in the flame-chamber and the consequent waste of heat.

In describing the invention reference will be had to the accompanyingdrawingsin which l have illustrated a preferred form of embodiment ofthe invention, it being' understood that ghanges in the details ofconstruction may be resorted to without departing from the spirit of theinvention as defined in the appended claims or sacrificing any of thead- Vantages thereof.

'ln thedrawings, Figure 1 is a view in hori zontal section, taken on theline l l, Fig. 2, and looking' in the direction of the arrow thereon.Fig. 2 is a vertical diamctral section through the furnace. Fig. 3 is adetail view showing the mechanism by which the movement of the travelinghearth is produced and the meehanism by which the hearth is guided inits movements.

Referring to the drawings, in which correspondingparts are designated bysimilar characters of reference, l designates the outer wall of thefurnace, which is constructed of brick, the inner. face thereof beingcovered with lire-brick, as shown. The wall l forms the circumference ofa circle of suitable diameter, the size which is most generally usedbeing thirty feet in diameter, inside measure ment. At intervalsthroughout the greater portion of its extent the wall lis provided withrectangular openings 2, having plates or slabs 3 of fire-brick disposedtherein at oblique angles to the outer surface of the wall. J ustexternal to each of the openings 2 is ar ranged a fire-box 4;, providedwith a grate 5, extending longitudinally of the fire-box and in contactwith the outer surface of the furnace-wall, as bestseen in Fig. f. Thefire-boxes and grates illustrated are of suitable proportions 'for theuse of oil as a fuel; but if it is IOO preferred to use coal or otherfuel instead of oilthe proportions of the fire-boxes and grates shouldbe altered to some extent. In the portion of the wall unprovidei'l withopenings 2 there are arranged two doors 6 and 7, respectively. Thelarger door 6 is provided for the introduction of the boxes into thefurnace, and the smaller door 7 is provided to facilitate the adjustmentof the boxes upon the hearth.

Concentric with the outer wall 1 of the furnace is an inner wall 10,which is also faced with fire-brick, as shown, and which surrounds acent-ral body 11 of ordinary brick, through which extendradially-arranged fiues 12, converging to a smoke-stack 13 at the centerof the furnace, which is provided at the top with a pivoted damper ofordinary form. The annular' space between the outer and innerfurnace-walls constitutes the flame-chamber, and this is covered with anarched roof of lire-brick 14.

As will be seen in Fig. 2, the flues 12 have their outer endssubstantially on a level with the lower portions of the openings 2 inthe outer furnace-wall, and their inner ends are at a slightly higherlevel, thus giving aslight upward slope toward the smoke-stack. Thearrangement of the outer ends of the flues 12 at the level of the lowerportions ofthe openings 2 is designed to obtain the maximum effeet ofthe flame which enters the furnace through the passages between theslabs 3 of fire-brick. The hearth, which consists of a mass' offire-brick 15. has its upper surface just below the outer ends of theflues 12, so that each box, as shown at 16, may lie directly between theopenings 2 in the outer wall and the fines 12 in the inner wall of thefurnace. As best seen in Fig. 2, the height of the flame-chamber of thefurnace is comparatively small, and the flame entering the furnace fromthe fire-box around the outer wall must necessarily strike against thebox mounted on the hearth and also be deflected down upon the box'fromthe arched roof over the flame-chamber.

The hearth 15 is of course arranged for movement in the furnace in orderto bring each portion of the hearth adjacent to the larger door of thefurnace and also to permit the boxes on the hearth to be moved steadilythrough the flame-chamber of the furnace during the process of heating,as it is practically impossible to obtain even in a furnace of theimproved type absolutely uniform distribution of heat within theflame-chamber. The preferred form of mechanism provided for impartingmovement to the hearth and guiding it in such movement is illustrated inF ig. 3. Upon reference to that figure it will be seen that the hearth15 is provided on its lower surface with T-rails 17 and 18, arrangednear the outer and inn er margins of the hearth, respectively, the rails18 being of greater height than the rails 17 for reasons which willpresently appear. The rails 17 and 18 rest upon trucks consisting of anaxle 19 and wheels 2O and 21, provided with flanges, as usual, andrigidly attached to the axle 19 at the outer and inner ends thereof,respectively. The wheel 21 of each truck is smaller than the wheel 2O tocorrespond to the difference in height of the rails 17 and 18 and to asimilar difference in height between rails 22 and 23, upon which thetrucks are supported. The heights of the rails 17 and 18 and rails 22and 23 are similarly related to the diameters of the wheels disposedbetween them, and the diameters of the wheels 20 and 21 are directlyproportional to their distances from the center of the furnace. Thisrelation in the size of the wheels and the heights of the rails is ofcourse adopted in order to insure the proper position of the trucks atall times and to prevent excessive friction in the operation of thehearth. The rails 22 and 23 are supported upon radially-arranged ironties24, supported some distance above the ground in order to provide apit for the reception of trash of any character which may be introducedinto the furnace. The proportions of the rails and wheels as describedabove are of suitable character to keep the trucks in substantiallyradial position at all times; but to prevent any slight inaccuracy inproportions from resultingI in an ultimate derangement of the trucks Iprovide chains 25 to connect the trucks and keep them at uniformdistances apart.

In order to keep the inner margin of the hearth suitably spaced from theinner wall of the furnace and to prevent wear upon the flanges of thewheels 2O and 21, I provide positivelyoperating spacing devices,consisting, preferably, of a horizontally-disposed rail 26, rigidlyattached to the web of the rail 18, an oppositelyarranged rail 27,mounted in a channel 28 in the inner furnacewall, and a plurality ofhorizontally-arranged flanged rollers 29, which travel between the rails26 and 27, as shown in Fig. 3. The, flanges upon the rollers 29 restupon the upper surfaces of the rails 26 and 27, and so prevent thedisplacement of the rollers from their position between the rails. Toprevent unequal distribution of the rollers by reason of any slightdifferences in their diameters, a chain 30 is used to connect therollers to hold them at uniform distances apart.

The mechanism for imparting movement to the hearth consists, preferably,of a rack 31, rigidly attached to the under surface of the hearth,external to the rail 17, and pinions 32, mounted upon shafts 33,journaled in the outer furnace-wall at dimetrically opposite points anddriven by any suitable devices. In the form of the invention illustratedeach of the shafts 33 is provided upon its outer end with asprocket-wheel 34, of suitable diameter, to

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outer furnace-wall.

rsasie which power is applied by means of chains 55, running over thesprocket-wheels and connecting the sprocket-wheels with a motor. (Notshown.

The operation of the furnace will be readily understood from aninspection of the drawings in the light of the foregoing description.The boxes containing the metal to be carbonized or decarbonized areintroduced through the larger door of the furnace, the hearth beingadvanced a sufficient distance after the introduction of each box topermit the insertion of the next, and the boxes are adjusted in positionafter insertion by implements introduced through the door provided forthat purpose. The boxes having been properlyT disposed upon the hearthof the furnace, the lires in the lire-boxes impart heat to the boxes asthe hearth is caused to travel slowly around in the annularflame-chamber. The direct action of the flames upon the boxes ismitigated by the obliquely-disposed deflector-plates 3 of lire-brickarranged in the openings 2 in the These obliquely-disposed plates causethe flames to enter the flamechamber at oblique angles to the peripherythereof, and so set up currents following the curve of the name-chamberinstead of going directly across it and into the flues leading to thesmoke-stack. This edect of the deliectorplates is advantageous 1ndiminishing the effect of the llame upon the outer sides of the boxes,which are most directly exposed thereto, and in also effecting a moreuniform distribution of the heat through the flame-chamber, so that inthe event of the heat from certain of the fire-boxes being greater thanthat from others the temperature in the flame-chamber will be in ameasure equalized by means of the currents following the curve thereof.The close proximity of the arched roof of the flamechamber to the topsof the boxes insures the contact of the liames with the tops of theboxes, and the disposition of the ends of the flues 12 just above theupper surface of the traveling hearth necessitates the downward passageof the flames along the inner wall of the flame-chamber before theyenter the flues and pass to the smoke-stack. rlhe slight upwardinclination of the flues 12 is effective in preventing any back draftfrom the smokestacl( and insuring the establishment of sulficient draftin all parts of the furnace.

From the foregoing explanation of the operation of the furnace it willbe clearly evident that the waste of heat inevitable in a furnace havinga circular flame-chamber is almost entirely obviated by the provision ofan annular flame-chamber in lieu thereof and at the same time thepossibility of producing a tolerably uniform temperature within the Theprovision of a flame-chamber results.

ll d

central smoke-stach with fines converging thereto from all parts of thefurnace renders possible the provision of lire-boxes around the greaterportion of the circumference of the furnace, and so permits theintroduction of heat at a large number of points.

The products of the improved type of furnace above described arecharacterized by greater uniformity than those of furnaces of theordinary type, as would naturally be supposed, and the boxes employed tohold the metal plates or bars to be carbonized last a much greaterlength of time in the improved furnace, because they are not subjectedat any time to excessive temperatures, and the scaling of the outersurface on account of the excessive heat is greatly lessened.

Having thus described the invention, what I claim as new, and desire tosecure by Letters Patent, is#

1. A furnace of the character specified having an annularflame-chamber,a central smokestack,a plurality of flues connecting saidchamber and stach, a plurality of grates external to said flame-chamberbut communicating therewith, and a plurality of deflector-platesdisposed between each of said lire-boxes and said flame-chamber todeflect the llames entering into said chamber.

2. A furnace of the character specified having an annularllame-chamber,a central smokestacli and a plurality of lines connectingsaid chamber and stack, a plurality of lire-boxes external to thefurnace-wall, but communieating with the flame-chamber, and a pluralityof deflector-plates arranged in said wall between said flame-chamber andthe lire-boxes to deflect the flames entering said flame-chamber.

, 3. A furnace of circular contour having an annular flame-chambertherein, and a plurality of fire-boxes external to the furnace-wall,said furnace-wall having a plurality of slots extending' obliquelythrough the wall adjacent to each lire-box.

Lf. A furnace of the character specified having an annularflame-chamber, an annular hearth disposed in said Haine-chamber,supporting-rails beneath said hearth, trucks provided on saidsupportingrails and havingl wheels whose diameters are proportional totheir distances from the center of the furnace, and rails attached tothe under surface of said hearth and resting on said trucks.

In testimony that i claim the foregoing as my own ,l have hereto affixedmy signature in the presence of two witnesses.

RUSSELL C. BLOOMFIELD.

Nitnessesz Guo. Laumer, JOHN Giurrrrns.

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